Molten salt-assisted anti-defect engineering to tailor ordered, highly crystalline g-C3N4 nanorods for efficient photocatalytic H2O2 production

Abstract

Graphite carbon nitride (g-C3N4) is widely recognized as one of the most popular catalysts for photocatalytic hydrogen peroxide (H2O2) production. However, it is often overlooked that general g-C3N4 materials contain numerous dangling bonds and defects, which serve as recombination centers for photogenerated carriers and significantly hinder their catalytic activity. Herein, we present a novel approach to address this issue by rationally tailoring well-ordered g-C3N4 nanorods (CNR) through molten salt-assisted anti-defect engineering. The resulting highly crystalline CNR demonstrates high efficiency in the artificial photosynthesis of H2O2. Experimental results indicate that enhancing the crystallinity of g-C3N4 while reducing the defect concentration effectively promotes charge separation and transport. As a result, it exhibits a remarkable H2O2 generation rate of 1.58 mmol g-1h−1 using air as the oxygen source, accompanied by an apparent quantum yield of 18.00 % (λ = 400 nm). The excellent photocatalytic performance of CNR surpasses that of all previously reported pristine g-C3N4 materials. This work sheds light on the effectiveness of molten salt-assisted anti-defect engineering in improving catalyst activity, with potential applications in solar cells, sensor devices and other catalytic systems.